A Model of Critical Phosphorus Concentration in the Shoot Biomass of Wheat

作者：Belanger Gilles^*; Ziadi Noura; Pageau Denis; Grant Cynthia; Hogna**acka Merja; Virkajarvi Perttu; Hu Zhengyi; Lu Jia; Lafond Jean; Nyiraneza Judith

来源：Agronomy Journal, 2015, 107(3): 963-970.

DOI：10.2134/agronj14.0451

Critical nutrient concentrations are required for assessing the level of crop nutrition. Our objectives were to validate an existing model of critical phosphorus concentration (P-c = 0.94 + 0.107N) in the shoot biomass (SB) of wheat (Triticum aestivum L.) and to assess the alternative approach of expressing P-c as a function of SB rather than shoot N concentration (N). We applied four rates of P fertilizer (0, 10, 20, and 30 kg P ha(-1)) on soils with a low to medium available P concentration at four locations in three countries (Normandin [Canada; 2010, 2011, 2012], Brandon [Canada; 2010, 2012], Ylistaro [Finland; 2010, 2011], and Beijing [China; 2012]) for a total of 8 site-years. Shoot biomass, and N and P concentrations were measured on five dates with 1-wk intervals from vegetative to late heading stages of development, and grain yield was measured. Increasing P fertilization did not increase grain yield at any of the 8 site-years and had little effect on SB. Under nonlimiting P conditions achieved in most cases with no applied P, the allometric relationship between P-c and SB differed among locations, while the relationship between P-c and shoot N concentration (P-c = -0.677 + 0.221N -0.00292N(2), R-2 = 0.82, P < 0.001) was independent of locations. This model of critical P concentration predicts lower P-c values than that previously reported, mostly for high shoot N concentrations. This predictive model of P-c can be used to quantify the degree of P deficiency during the wheat growing season.

• 出版日期2015-6
• 单位中国科学院大学